Vibrating tamping device



Feb. '3, 1970 T. FORS ETAL 3,492,924

VIBRATING TAMPING DEVICE Filed July 17, 1968 INVENTORS. TORSTEN FORS 8| ESKIL' TUNEBLOM their ATTORNEYS.

United States Patent 3,492,924 VIBRATING TAMPING DEVICE Torsten Fors, Vallingby, and Eskil Tuneblom, Kallhall, Sweden, assignors to Aktiebolaget Vibro-Verken, Solna, Sweden, a corporation of Sweden Filed July 17, 1968, Ser. No. 745,561 Claims priority, application Sweden, July 19, 1967, 10,698/67 Int. Cl. C01c 19/24 US. CI. 94-49 4 Claims ABSTRACT OF THE DISCLOSURE A vibrating tamping apparatus for compacting earth, concrete, asphalt and other materials capable of being compacted, which includes a motor unit positioned over and coupled to a compacting unit. A reciprocating rod that extends from the motor unit drives and vibrates the compacting unit, and the linkage system movably connects the two units in such manner that movements produced by irregularities in the surface being compacted can be effectively absorbed by the linkage without the need for an additional guide structure between the units.

The present invention relates to tamping apparatus for compacting earth, concrete, asphalt and other materlals which can be compacted and in which vibratory or tamping movements, in addition to compacting the material, also move the apparatus forwardly.

Vibratory tamping machines which provide substantially vertical tamping movements have, in the past, in cluded motor units and compacting units coupled by guide structures such as pistons and cylinders. Such guide structures, while functioning to maintain the two units in proper relation one to the other, were subject to excessive wear even when provided with an effective lubrication system. Further, it was necessary to preclude the entrance of dust and dirt into the guide surfaces by bellows or other sealing devices which complicated the tamping device.

The present invention overcomes the above enumerated disadvantages of tamping machines by providing a linkage system movably connecting the motor unit and compacting unit together without the need for wear-sensitive guide structures requiring lubrication and protection from dirt and dust. A simple reciprocating rod extending from the motor unit is coupled to and drives the compacting unit.

More particularly, the linkage system connecting the motor unit to the compacting unit includes a first arm extending outwardly in one direction from the motor unit over the compacting unit and a second arm extending outwardly in the other direction from the compacting unit under the motor unit. Links respectively join the first arm pivotally to the compacting unit and the second arm pivotally to the motor unit, and the linkage system is arranged to provide as great a distance as possible between the pivot points on the motor unit and compacting unit to enable the linkage system to compensate for and absorb movements due to irregularities in the surface being compacted and yet facilitate driving of the compacting unit by the reciprocating rod.

In a preferred embodiment of the invention, the tamping device is of such size that it can be operated by one man and the substantially vertical tamping or vibrating movement is imparted to the compacting unit by a crank mechanism incorporated in a drive motor in the motor unit. The mass of the two units is selected so that the motor unit moves only slightly in the vertical direction during the tamping or vibrating movement of the compacting unit and the angular relationship of the two units 3,492,924 Patented Feb. 3, 1970 is such that the tamping device is caused to move forward by the vibratory motion.

These and further advantages of the invention will be more readily understood when the following description is read in conjunction with the accompanying drawings, in which:

FIGURE 1 is an elevation of a vibratory tamping device embodying the principles of the present invention; and

FIGURE 2 is a cross-section of the tamping device taken along the line 22 of FIGURE 1 looking in the direction of the arrows.

Referring to a typical embodiment of the present invention with particular reference to FIGURE 1, an inclined motor unit 1 is located above and slightly forward of a compacting unit 2. A compactor shoe 3 positioned on the lower portion of the compacting unit has upturned forward and rearward edges and is designed to resist wear while compacting earth, concrete, asphalt and similar materials.

The motor unit 1 includes a drive motor 4, which may be a gasoline or diesel engine, and which, through a crank-type mechanism, imparts to a reciprocable rod 5 a substantially vertical reciprocating movement.

At its lower end the rod 5 is connected resiliently to the compacting unit by coil springs 6a and 6b which bear against a plate 5a on the lower end of the rod. A tubular casing 7 enclosing the springs 6a and 6b is secured at its lower end to the compactor shoe 3 and includes adjacent its upper end an annular plate 7a including an opening 7b through which the rod 5 passes.

To locate the motor unit 1 over the compacting unit 2 and yet permit relative motion therebetween to absorb movements of the compacting unit due to irregularities in the surface being compacted, a linkage system is provided between the two units which includes a pair of links 8 pivoted on pins 12 mounted on the casing 7 and a pair of links 9 pivoted on pins 14 mounted on the motor unit 1. Preferably the pins 12 and 14 are resiliently mounted, for example, by the use of shear stressed rubber elements (not shown).

Also included in the linkage system, in order to obtain the longest possible distance between the link pairs 8 and 9, are arms 10 and 11 respectively fastened to and extending from the motor unit 1 and the compacting unit 2. In particular, the arm 10 extends rearwardly and downwardly over the compacting unit 2. For sutficient strength and rigidity, the arm 10 is formed with a C-shaped crosssection, as shown in FIGURE 2, and is secured to opposite sides of the motor unit 1. At its free end, the arm 10 carries a pair of pivot pins 13 upon which the links 8 pivot.

The arm 11 extends forwardly and upwardly under the motor unit l'and carries pins 15 at its free end upon which the links 9 are pivoted. The arm 11 may also be formed with a C-shaped cross-section and fastened to opposite sides of the casing 7 on the compacting unit 2.

In order to guide the tamping device, a frame 16 suitably mounted on and fastened to the motor unit 1 includes a pair of hand grips 17 and supports a tank 18 holding fuel for the motor 4. To dampen vibrations which would otherwise be transmitted from the compactor shoe 3 through the motor unit and then to the hand grip 17, special resilient attachment structures 19 couple the hand grip 17 to the frame 16.

In operation, the motor 4 is started in the conventional manner to inititate reciprocating movement of the rod 5. The operator then merely guides the direction of the tamping apparatus which, because of the inclined mounting of the motor unit 1 over the compacting unit 2, moves forwardly while vertical compacting forces are applied to the surface on which the compactor shoe 3 rests. Displacement of the compacting unit 2 with respect to the motor unit 1 by irregularities in the surface along which the compactor shoe 3 travels are efiectively taken up by the linkage system due to the relatively large distance'between' the pivot points 12 and 14 on the compacting unit and motor unit, respectively. Consequently, it is not necessary to use pistons, cylinders or other guide structures to provide a substantially vertical tamping movement in the compacting unithence it is not necessary when using the inventive device to use special protective casing in the form of bellows or the like to prevent the entrance of dirt or dust to such sensitive guide structures.

It will be understood that the above-described embodiment of the invention is illustrative only and modifications thereof will occur to those skilled in the art. Therefore, the invention is not to be-limited to the specific apparatus disclosed herein but is to be defined by the appended claims.

We claim:

1. A compacting device comprising a motor unit, a rod reciprocated substantially vertically 'by the motor unit, a driven compacting unit including means coupled to the rod, and linkage means for mounting the motor unit over the compacting unit including a first arm extending outwardly in one direction from the motor unit over the compacting unit, first link means pivotally connecting the 4 first arm to the motor unit, a second arm extending outwardly in the other direction from the compacting unit under the motor unit, and second link means pivotally connecting the second arm to the motor unit, so that the motor unit and compacting unit are movably connected together.

2. Apparatus as defined in claim 1, wherein the extension of the first arm is partially downwardly towards the compacting unit and the extension of the second arm is partially upwardly under the motor unit.

3. Apparatus as defined in claim 2, wherein the first link means comprises a pair of links extending from the first arm to opposite sides of the compacting unit and the second link means comprises a pair of links extending from the second arm to opposite sides of the motor unit.

4. Apparatus as defined in claim 1, wherein resilient means in the compacting unit are coupled to the reciprocating rod.

References Cited UNITED STATES PATENTS 3,017,810 l/1962 Jacklin 94-48 3,109,354 11/1963 Van Kirk 9449 3,308,729 3/ 1967 Kestel 9449 JACOB L. NACKENOFF, Primary Examiner 

